ENZYMES: coenzymes

Question 1

define: cofactor

Answer 1

non-protein portions of enzyme molecules that contribute to enzyme function and stability.

Question 2

tyoes of cofactors?

Answer 2

organic/inorganic cofactors

Question 3

what are inorganic cofactors?

Answer 3

includes metal ions and clusters of many ions (eg. Zn2+ for DNA polymerase)

Question 4

what are organic cofactors?

Answer 4

there’s 2 types

Question 5

what are 2 types of organic cofactors?

Answer 5

prosthetic groups and coenzymes

Question 6

define: prosthetic group

Answer 6

organic molecules that are tightly bound to an enzyme (eg. catalase has 4 pp’s, each has a heme group tightly bound)

Question 7

define: coenzyme

Answer 7

an organic cofactor; can’t function alone but assist enzymes in reactions involving transfer of protons, electrons and erergy. They are NAD+/NADH, NADP+/NADPH, ATP

Question 8

describe NADH

Answer 8

• Involved in metabolic pathways requiring redox reactions – transferring electrons and protons (H+)

Question 9

describe loaded form of NADH

Answer 9

NADH. It can donate electrons (be oxidised) – helper for enzymes which catalyse reduction reactions.

Question 10

describe unloaded form of NADH

Answer 10

NAD+. It can accept electrons (be reduced) – helper for enzymes which catalyse oxidation reactions

Question 11

what is the NADH reaction?

Answer 11

NAD+ + H+ + 2e- NADH

Question 12

NADH is present in

Answer 12

animals (cellular resp?) ASK

Question 13

NADPH is present in

Answer 13

plants (photos??)

Question 14

Describe ATP

Answer 14

Involved in metabolic pathways requiring energy transferral.

Question 15

atp reaction?

Answer 15

ADP + Pi (inorganic phosphate) + energy ATP + H2O